Preppcomm Mmx zero User manual

MMX ZERO

Morse Code

Decoder/Encoder!

REFERENCE MANUAL

By Eric C Anderson

PreppComm

Version 1.1, July 2023

Page 2

Morse Made Easy™

MMX ZERO

Morse Code Decoder/Encoder!

REFERENCE MANUAL

By Eric C Anderson

PreppComm

Version 1.1, July 2023

Page 3

Page 4

Table of Contents 
Overview" #----------------------------------------------------------------------------7
Warranty and Cautions" #-------------------------------------------------------------9
1 Important Notice: Things Not Covered by the Warranty" #............................9
2 The Elephant(s) In The Room" #......................................................................9
3. Getting Started... Quickly" #.........................................................................10
Getting Acquainted" #---------------------------------------------------------------11
Setup with your External Transceiver" #--------------------------------------------13
Power On Walk Through" #----------------------------------------------------------14
Menus" #------------------------------------------------------------------------------17
1 Local Station Setup" #...................................................................................18
2 Typing Speed" #............................................................................................19
3 Microprogramming" #....................................................................................21
Keyboard Controls" #----------------------------------------------------------------23
1 Receive Mode Keyboard Commands" #.......................................................23
2 Decoder Mode Control Keys" #....................................................................24
3 Gain Control Keys" #.....................................................................................25
4 Editing Keys" #..............................................................................................25
8 Function keys" #............................................................................................26
9 Miscellaneous Receive Mode Controls" #.....................................................26
10 Transmit Keyboard Controls" #....................................................................26
Decoder Operation" #----------------------------------------------------------------29
1 HCW Mode" #................................................................................................29
2 CTX Mode" #.................................................................................................31
3 Switching Modes" #......................................................................................31
4 Tuning a Station" #........................................................................................31
5 Setting up your transceiver" #.......................................................................33
CALLING" #---------------------------------------------------------------------------37
2 General Calling" #..........................................................................................37
3 Setting Transmit Speed" #.............................................................................38
4 Setting a New Default Transmit Speed" #.....................................................39
5 The CALL Sequence" #.................................................................................39
6 Setting Up a Directed Call" #.........................................................................40
Copyright © 2023 PreppComm
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7 Three Ways For Establishing a CCS" #.........................................................40
8 What Happens After You CALL?" #...............................................................42
ANSWERING" #----------------------------------------------------------------------43
1 The ANSwer Validate and ANSwer Microprogram" #..................................44
2 The ANSwer Validate Component" #...........................................................44
3 The ANSwer Start Component" #...............................................................45
4 The Pop-Up Type-Ahead Buﬀer" #..............................................................46
5 Sending Your Message" #...........................................................................47
6 The ANSwer Ending Component" #............................................................48
7 The INFO Microprogram" #.........................................................................48
8 What Happens After an ANSwer?" #...........................................................49
Appendix I: Pro-Signs and No-Signs" #-------------------------------------------50
Appendix II: Special Characters" #-------------------------------------------------51
Appendix IV: Terminology" #--------------------------------------------------------53
Appendix V: RPL and User Microprograms" #------------------------------------55
1 Introduction" #.............................................................................................55
2 The Built-In Microprograms" #....................................................................55
3 Microprogram Types" #...............................................................................56
4 RPL Control Characters" #..........................................................................57
5 Built-in Microprogram Review" #.................................................................60
6 Inserting Into a Running CALL or ANS Microprogram" #............................62
7 The Microprogram Editor" #........................................................................62
8 Microprogram Help" #.................................................................................65
9 Some Examples" #......................................................................................66
10 The Starter Set" #......................................................................................67
Appendix VI: Keyboard and RPL Command Layouts" #--------------------------68
Appendix VII: Common CW Abbreviations" #-------------------------------------74
Appendix VIII: The Tuning Rule Graphically Explained" #-------------------------76
Appendix IX: Alternate USB Keyboards" #-----------------------------------------78
Wiring the 3.5 mm Jacks"---------------------------------------------------------79
Page 6
Copyright © 2023 PreppComm

1. Overview

Congratulations for purchasing the new MMX ZERO Morse Code Decoder/Encoder! The MMX

ZERO was created to provide a texting interface to the user for operating on CW, making

communications via Morse code similar to texting on a modern smartphone: simple, easy, and fun!

It also provides a fantastic platform for learning Morse Code, should the operator have the interest in

doing so. And by the way, learning it even if you don’t want to. The learning happens when you have

QSO’s automatically.#

The ZERO is easy to operate, due to its graphical user interface, presented on a 3.5" color

touchscreen display. In addition, an included USB/PS2 keyboard is utilized to provide text input as

well as control functions.#

While the device can be seen as a simple tool for non-technical operators, it also includes many

advanced features often not found in much more expensive equipment:#

1. Automatic code speed setting: transmitter speed set from received code speed#

2. Hyper-active tone extractor and powerful digital ﬁlter to extract text in high-noise situations,

with extreme noise immunity. The decoder can copy fading signals you can’t hear under the

noise!#

3. Super selective decoder (160 Hz wide sensitivity) without audio ﬁltering - you hear full 100 -

10,000 Hz audio, but the decoder only hears a tiny slice around the set tone frequency,

approximately 1220-1380 Hz.#

4. Automatic capture of remote station call letters. I love this one!#

5. Built-in typing speed calibration to limit transmit speed to your comfortable speed, to prevent

starving the transmitter while transmitting because the other station can send Morse faster

than you can type Morse#

6. 76 character type-ahead pop-up buﬀer for keeping ahead of the transmitter and correcting

mistakes before they go out, including an automatic station ID to give you time to get ahead

of the transmitter at the beginning#

7. Built-in microprograms for calling, answering, and sending information (CALL, ANS, and

INFO)#

8. 12 User deﬁnable microprograms for customizing operational modes and messages, using a

powerful microprogramming language#

9. Full function microprogram editor#

10. Word wrap display for easy reading of incoming and outgoing text.#

Thus, for the more advanced user, the MMX ZERO can provide an excellent choice for enabling or

enhancing their CW communication. It can also easily be placed into an EMP protective container for

the purpose of having it available in case of an EMP event, as well. We oﬀer the Transceiver EMP

Bundle for this purpose.#

Using the Reference Manual

The manual is written sequentially for you to go through and learn how to use your transceiver. It is

also designed as a reference manual, by including all relevant information under any given topic.#

Page 7

Several Appendices are provided at the end of the manual with keyboard layout diagrams and other

tables that can be copied or printed out to use to support the learning process. Also a terminology

appendix is included in case you need help with any terms you don’t understand.#

Under the Hood

For those of you with technical interest, the MMX is based on a triple-processor real-time multi-

tasking system architecture. A complex dance of real-time interaction between three interrupt-

driven real-time processors makes the magic of the MMX possible.#

Page 8

2. Warranty and Cautions

The one year warranty for this unit is against defects in material and workmanship for a period of one

year. The software is provided “as is.” Occasional software updates will be provided, but due to the

triple processor architecture, the MMX must be returned to the factory for software updates.#

2.1 Important Notice: Things Not Covered by the Warranty!

3. Carefully align and plug connectors - do not force. The side mounted USB and audio

connectors are mounted on the surface of the front printed circuit board. They can be broken oﬀ

from the circuit board if excessive force is used when plugging in a cable. This type of damage

is not covered by the warranty. Our upgraded cabinet holds the connectors tightly, and should

prevent any accidental damage.%

4. Do not scratch or gouge the touch screen with a sharp object. The touch screen is not like

the capacitive touch screen on your cell phone, but rather a less expensive resistive touch panel.

This means it requires a little more force, and that there is a thin plastic layer with invisible wires

over the glass. It can be cut with sharp objects, which will disable all or part of the touch

function. Also, too much pressure on the screen can crack the glass, which can also cause

touch failure and ultimately LCD failure. Use a rounded tip or eraser end of a pencil if you want to

avoid ﬁngerprints. Use the included microﬁber cloth to clean oﬀﬁngerprints. You can also

create microprograms to replace pressing some of the buttons on the Main Screen if you wish so

they can be accessed directly from your keyboard. Finally, use the lid provided to protect the

front panel and LCD when not in use. Physical damage to the front panel, such as damaged

LCD, or damaged LED’s is not covered under the warranty.!

5. Take care how you run the keyboard cable. The keyboard cable can act as an antenna and

pick up RF from your transmitter, especially if you have RF in the shack. A low SWR antenna

with a good ground or a balanced antenna with a 1:1 Balun will eliminate most RF in the shack

problems.#

2.2 The Elephant(s) In The Room#

The Big Elephant: 1300 Hz. Yup, you heard that right. Or maybe you didn’t hear it if you have

hearing problems. The ZERO does NOT decode your favorite 600 or 650 Hz tone on CW. It operates

at about twice the usual frequency This can be hard to get used to. In addition, setting up your

transceiver for 1300 Hz operation is diﬀerent than you expect. We have a blog on how to do it for an

IC-7300 on the website. Locate the Blog menu item along the top of the home page, and click. You

will see several blogs. Scroll until you see the IC-7300 image. That’s the one. Here is the link if you

are reading this on PDF:#

https://www.preppcomm.com/blogs/news/setting-up-an-icom-7300-for-1300-hz-tones#

Page 9

Follow this example for your own transceiver. And order our External Transceiver Cable Assembly

if you have not done so already. It will make connecting the ZERO to your rig easy, and look great in

your shack. A MMX/DMX Stand is also a good choice as it holds the ZERO at 45° so it is easier to

read.#

The Second Elephant in the room is ... experience. While we may Morse easy, we don’t make

learning CW easy. CW is a lot of things besides just the code. CW is about frequencies, methods,

operating styles, abbreviations, and much more. Once you learn it, you can quickly tune around the

band, and know when you are receiving a fellow amateur or hearing a digital transmission that is

decoded as gibberish. Also there is some expertise you will gain over time on adjusting the decoder

gain, and the receiver frequency, determining which of the two sides of the signal you are on, and

selecting the correct one. And being aware of band conditions, which are related to time of day,

sunspots, and other factors. Do not be disappointed if you don’t make any contact on your ﬁrst try!

Patience and practice are very important.#

One other thing: this one messed me up when I started. There are stations on there that are actually

transmitting what appears to be random junk. It is not random junk, it is data, sent via Morse Code.

Best way to start is to call CQ or listen for someone calling CQ. Don’t be fooled into thinking the

decoder is not working by a data station!#

If you have a buddy across town, or across the valley that does CW, that is a great way to start.

That way, you can learn the ropes with someone you can talk to over the phone if things are not

working the way you expected. So, initially, ﬁnding a local ham operator with Morse code

experience, or someone with an MMX, ZERO or DMX-40 of their own to get some on-the-air

experience with is an excellent way to gain conﬁdence and experience.#

2.3. Getting Started... Quickly#

We have provided a Quick Start Guide (separate ﬁle) to enable you to get started quickly with your new

transceiver. We recommend using that as a starting point, and then using this Reference Manual to ﬁll in the

gaps in your knowledge of the various functions and features that are not covered in the Guide. We have

included many cross links within the document, as well as Table of Contents links and a back link at the top of

every page to get you back to the Table of Contents with a single click. This greatly enhances exploring the

contents of the manual.#

As mentioned before, there are a number of appendices that you should check out early on. We recommend

you print out the keyboard command charts, for example, to have next to you as you are learning how to use

the various features of your new transceiver. At ﬁrst, that might seem to be a daunting task, but practice a

little, and it will become second nature.#

As always, we love to hear from our customers, so if you have questions, comments, or suggestions, please

use the Contact Us page on our website:#

https://PreppComm.com

You can also get help from the PreppComm Community at:#

http://PreppComm.mn.co

Page 10

3. Getting Acquainted

Figure 1 is a labeled diagram of the MMX ZERO:#

3.5" Color LCD Display

At the center is the 3.5" color LCD display, which is also a touch screen input device. #

Key In/Out Jack!

This is a stereo 3.5mm jack that has one channel dedicated to Key Out, when used with an external

transceiver (External Mode). The other channel is dedicated to support a Morse Code key for

manual code entry for training and on-air use, if desired. See Appendix X for a wiring diagram.

Audio In Jack

The Audio In jack is used to connect the audio output from an external rig to the internal decoder

(External Mode).#

USB Keyboard

This is a USB-A female connector for connecting the included USB/PS2 keyboard to the MMX.#

Page 11

FIGURE 1. MMX ZERO

CW Out LED

This blue LED displays the outgoing Morse code when the transceiver is in transmit mode (either

with or without the internal transceiver engaged).#

Enabled LED

This green LED indicates when you have set the frequency to one you are allowed to transmit on,

based on the license level you have speciﬁed in local station setup. If the unit is in External Mode,

the LED is always lit, and it is up to you to manage your external rig frequency setting when

transmitting..#

CW In LED

This green LED indicates what the computer is seeing as Morse code input. It represents the

considered opinion of a complex set of analog and digital signal processors, and is a very accurate

representation of the incoming Morse code signal. This LED is used to assist tuning the receiver to

center on the frequency of the sender.#

Tone LED

This yellow LED indicates the output of just the analog portion of the signal processing system. This

LED is normally ﬂickering from noise, as well as lighting brightly during a strong Morse signal. This

LED is helpful for adjusting the decoder gain correctly. Decoder gain is controlled from the

keyboard.#

Power LED

This LED is lit when the power is applied to the internal circuitry.#

Power Switch

This is a push-on/push-oﬀpower switch for controlling the power to the unit.#

5V USB Mini Power Connector

The ZERO is powered by 5V via an included USB cable. The USB A plug can be powered from a

laptop, a computer, an outlet strip with a USB output, or a wall plug with USB outputs. Total current

draw is about 0.25A.#

Page 12

4. Setup with your External Transceiver

Connecting up to your base station or portable transceiver is quite simple, especially if you use our

External Transceiver Cable Assembly, shown in Figure 2 below#

In the diagram above, we use the External Transceiver Cable Assembly accessory, available on

our website. This cable set has everything you need to connect the two 3.5mm jacks (KEY IN/OUT,

AUDIO IN) on the MMX to your external rig (KEY IN, HEADPHONE OUT) as well as a plug for a

powered speaker and an external straight key, if you so desire. If you wish to use paddles or an

iambic paddle, an external keyer that converts from those dual-contact formats into pure Morse is

required.#

Page 13

FIGURE 2: EXTERNAL MODE SETUP FOR MMX

5. Power On Walk Through

Once you have set up your transceiver, press the Power switch, you will immediately see the splash

screen appear, as shown in Figure 3#

Note that this is the same screen as the multi-band MMX, as it is really the same product, with the

transceiver removed. This screen will be present for a few seconds, and will then be followed by the

Main Screen, shown in Figure 4. Each item on this screen is described below.#

Page 14

FIGURE 3: SPLASH SCREEN

FIGURE 4: MAIN SCREEN

At some point, perhaps we will replace the screen graphics on the ZERO so it is diﬀerent from the

multi-band MMX. But for now, they have the same graphic..#

Text Area

Most of the screen is dedicated for text - both for received text from other stations, and transmitted

text from you. The initial screen shows the PreppComm logo, but this will disappear as soon as the

space is needed. Text you transmit is shown in blue. Text you receive is shown in light gray. The

text area is 37 characters wide and 10 lines high, and is fully word-wrapped - i.e., automatic

wrapping to the next line always occurs on word boundaries for easy reading. You cannot directly

type into this space: only the encoder (transmitter) and the decoder (receiver) can place text here.

Of course you do type most outgoing encoder text for the transmitter, but that ﬁrst appears on the

type-ahead buﬀer lines. It only shows up in the text area as it is transmitted.#

Status Line

The Status Line of text is shown below the button line, and is always white text. In Figure 5. The

Status Line shows "HCW: Collecting Data..." This indicates that the decoder is in HCW mode, and

is searching for data to determine the speed of the sender, and analyzing ﬁve key characteristics of

the sender’s technique. Finally, the Status Line is also a button. Pressing it turns the black

background blue (while being pressed) as visual feedback, and restarts the decoder if you are in

Receive Mode. This allows decoding with no keyboard, as decoder restarts can be done from the

touch screen.#

Decoder Gain

The decoder gain is set to 30 in Figure 5. The range is from 0 to 40. Keyboard commands < and >

are used to control this value.#

Volume Level

Since there is no transceiver inside, there is also no audio output, and thus, this control is not

functional on the ZERO.#

CALL Button

This button controls the sequence of events required for you to make a Directed Call (to a speciﬁc

station) or General Call to anyone (Calling CQ). More on the operation of this control in Section 9. A

CALL in progress disables all other buttons on the main screen.#

CCS Button

CCS stands for Captured Call Sign. The decoder has the ability to automatically capture the call

sign of another station you are listening to. Details on that function are described later in Section 9

and Section 10. NO CCS means just that. This display area is also a button, which allows manual

control over the CCS value,#

ANS Button

ANS is an abbreviation for ANSWER. This is the other transmit mode. This button provides two

separate functions. The ﬁrst is what we call the answer-validate function, to see if the other station

can hear you and thus establish a 2-way conversation. In addition, it allows you to answer back to

the other station you are in a conversation with. Like the CCS Button, it has some advanced

Page 15

functionality we will discuss in Section 10. An ANS in progress disables all other buttons on the

main screen.#

Frequency Button

This button will always display External, due to the lack of a built-in transceiver. Because of that,

pressing it does nothing, so in eﬀect, it is not functional in the ZERO.#

Menu Button

This button brings up the menu, which will be described in Section 8. Also note that while the

receiver is still active when you enter the menu and its related functions, any decoder output

received during the menu function will be lost. Thus, don’t use menu functions while receiving text

from another station.#

Type-Ahead Buﬀer Pop-Up (not shown)

A pop-up "window" for typing your message ahead of the transmitter will appear near the top of the

text area on the screen. This is a two-line buﬀer containing up to 76 characters. This pop-up is

described in more detail in Section 10.4.#

Page 16

6. Menus

The menu system is fairly simple on the MMX. Figure 5 is the screen displayed when the MENU

Button is pressed. Graphics and ﬁrmware versions are shown at bottom left and right corners (not

shown here):#

There are only 6 options on the menu screen, besides EXIT MENU, which returns you to the Main

Screen. They are:#

LOCAL STATION SETUP

This menu item is primarily used the ﬁrst time you power up, and infrequently used thereafter. More

details for station setup are described in Section 8.1.#

HELP

This button brings you to a second menu screen, where you can select between RECEIVE,

TRANSMIT, and MICROPROGRAMMING or of course EXIT MENU. #

The ﬁrst two get you to the keyboard command list when in receive or transmit mode, and the third

gets you to the list of commands in the microprogramming language that is used in the 12

microprograms you can create to optimize the operation of the MMX to suit your preferences.#

VFO ADJUST

As there is no VFO in the ZERO, this button will give you a “External Mode” warning, rather than the

VFO setting screen.#

TYPING SPEED

The default typing speed is set to the maximum MMX transmit speed, or 60 WPM. This is not likely

to be your comfortable typing speed, so you should select this option, take the speed test, and get

the maximum speed reduced to your comfortable typing speed, This feature prevents starving the

transmitter from your text input, which would generate badly timed Morse code output. More details

in Section 8.3.#

Page 17

FIGURE 5: MAIN MENU SCREEN

MICROPROGRAMMING

This button accesses the Microprogram List pages. These will be discussed in detail in Section 8.4.#

MHz MEMORIES

Frequency memories are not useful or functional without a VFO to send them to, so this button is

also not functional.#

EXIT MENU

This button returns you to the Main Screen.#

6.1 Local Station Setup#

This menu item is designed for you to provide necessary information to the transceiver about your

local station, and leads to a series of display pages to collect from you a set of information to be

stored in internal memory. The ﬁrst screen is shown in Figure 6 below, to collect your call letter#

As you can see, the screen text prompts you to enter your call letters. Note that the computer

always capitalizes your alphabetic characters, so you don’t have to use the shift key to capitalize.

You can use either the Delete and Backspace key to delete a character for editing purposes.

Simply type in your call letters, and press the Next button to enter your call letters into memory.#

Normally, amateur radio call signs are a minimum of 4 characters, and a maximum of 6 characters.

We allow from 3 to 9, so you can add extra characters at the end of your call sign, such as W2OL/

RM. for W2OL Remote. Also, there are some uses of the MMX where military units will use them,

and they can have 3 character call signs.

Pressing the NEXT Button will bring you a very similar screen, but in this case, it is asking for your

handle, or name. The progression of entry screens in Local Station Setup is as follows:#

"1. Call Letters#

Page 18

FIGURE 6: STORING YOUR CALL LETTERS

"2. Handle or Name#

"3. QTH or Location#

"4. Rig Type" #

"5. Antenna Type#

"6. License Level#

This information is used to create the INFO microprogram. Pressing the ﬁnal Next Button on the

Antenna screen will display the License Select Screen, which uses radio buttons rather than text

input, as shown in Figure 7 below:#

Since you are using an external transceiver, this function cannot limit the frequency that you set on

that rig, so it is not functional. Any value will do. Press FINISH to return to the main screen.#

6.2 Typing Speed#

This function will bring up the following screen, shown in Figure 8 below:#

Page 19

FIGURE 7 LICENSE LEVEL ENTRY SCREEN

FIGURE 8: TYPING SPEED TEST

The purpose of establishing your comfortable or "normal" typing speed is to prevent the transmitter

from getting away from you, into a situation we call "starving the transmitter." In this situation, you

are unable to keep up with the transmitter. This causes two separate problems:#

1. The transmitted code falls into a timing situation where each letter is sent as a word, rather than

a single letter as part of a word. This is very unhelpful for the person at the other end trying to

decode what you are sending.%

2. You, the operator, realizing that the transmitter is starved, tend to panic, and start making typing

mistakes, adding even more trouble for the person decoding at the other end.#

Avoid the by taking this simple test to determine your typing speed.#

The reality is, this IS a test, and you will try to beat the clock. It’s simply human. Show the computer

how fast you can type the line! Well, that is counter-productive, so the number suggested by the

computer on the very next screen takes that into account, shown below in Figure 9 on the next

page. This screen pops up automatically when you ﬁnish the sentence.#

Here, we see the computer measured a typing speed, and assigned its best guess: 22 WPM. Of

course you can edit this screen to change the value via the keyboard. It starts out at 60 WPM on

ﬁrst boot, and you should either take the test, or click on the NEXT button on the "Calculate Normal

Typing Speed" screen, and enter any value you choose without taking the test, using BACKSPACE

to delete 60 ﬁrst.#

The computer’s best guess, for me, was still a little high, even though it is substantially lower than

my actual speed measured during the test. That is because - even though told to relax and type at a

comfortable rate, I typed at a "speed to the death" rate. There is something about how our minds

work: YIKES! This is a TEST! Gotta type it fast!#

Page 20

FIGURE 9: SETTING THE MAXIMUM TRANSMITTER

SPEED

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